In the construction of a stairway, one of the first things which must be done is to determine the pattern and dimensions of the threads and risers. This, of course, is a function of the total horizontal run and vertical rise of the stairway, with the width of the tread of each stair being normally, for example, 10 inches. These dimensions are, of course, highly variable, depending upon the particular construction project. For example, if the total rise of the stairway is 87 inches, it would be advisable to provide 12 risers in which the height of each riser is 7.25 inches. In the instance that a horizontal run of 110 inches is required, the number of treads present may be 11, and their width can be 10 inches.
In the prior art, this calculation is often arrived at experimentally by scribing various patterns of the risers and treads, frequently with much erasing and reworking, until a uniform pattern which fits the specific situaton is arrived at.
In accordance with this invention, a template is provided for simplifying the scribing of the tread and riser lines on the side boards for the construction of a stairway, or similar purpose. After the desired dimensions for the tread and riser are calculated, the template may be set with the desired dimensions. The template may then be placed along the edge of the pieces of plywood which will define the sides of the stairway. Then the respective tread and riser lines will be sequentially scribed along the square edges of the template, simply moving the template along the edge of the plywood and scribing the various tread and riser lines, to the completion of the project, without any need to measure distances along a conventional square or the like.
Furthermore, the accuracy of the template of this invention can be very high, so that, with proper calculation, the scribed tread and riser lines will be placed evenly and in their proper places along the side supports of the stair, without the need for "fudging" the results to fit the various tread and riser lines in. The side supports are then cut along the tread and riser lines, permitting attachment of the treads and risers.
The result of this is a uniform stairway, which simplifies its construction and provides higher quality work.